Audiovisual distribution system

ABSTRACT

Audiovisual distribution system in which each of the audiovisual units ( 8 ) includes means for interactively communicating with the user for selecting a piece or a menu, payment means, a computer network card, a permanent semiconductor memory containing a multitask operating system comprising at least a hard disc access management task. The order for performing a selected piece is processed as a hard disc sequential access task. The hard disc is declared as a peripheral corresponding to the network card of the unit, enabling a request to be sent through the network to a server ( 9 ) for processing thereof.

[0001] This invention relates to an audiovisual distribution system forplaying an audiovisual piece on at least one audiovisual device fromamong a plurality of audiovisual devices linked in a network to acentral server.

[0002] Networks exist which make it possible to produce music from ajukebox-type device by frequency multiplexing a musical selection on acable network of the coaxial cable type used to distribute televisionchannels. A device such as this one is known from patent EP 0140593. Ithas the drawback that it requires conversion boxes to demultiplexsignals, and it uses a network of the coaxial type involving—for onechannel—distribution of the same selection to all stations.

[0003] A first object of the invention is to allow the network todistribute as a matter of choice either the same selection to all thedevices, or a different selection to each individual device; theselection can be either of the audio or video type.

[0004] British patent 2193420 and patent PCT WO 9415416 also discloseaudio selection distribution networks requiring telephone lines. Due tothe use of these telephone lines, network transmission speeds arelimited and a network such as this cannot be used for distribution ofvideo selections requiring a high transmission speed to allowgood-quality video reproduction.

[0005] PCT patent WO 9415416 discloses use of a telephone line of theISDN type, but even this type of line—the transmission speed of which islimited to 18 megabits per second—is not sufficient to distributegood-quality video data to a sufficient number of devices.

[0006] Finally, another object of the invention is a network in whichthe costly elements are transferred to the level of the server to reducethe cost of each audiovisual reproduction device, but without detrimentto their performance. These costly elements are high-capacity hard disksallowing storage of a sufficient number of data selections, inparticular video, and also telecommunication modem with transmissionspeeds allowing the network to be linked to a central system servicing aplurality of networks.

[0007] This object is achieved in an audiovisual distribution systemwhich—in order to play an audiovisual piece on at least one audiovisualdevice from among a plurality of audiovisual devices, each comprised ofaudio or video means for playing a piece and linked to a centralcomputer server containing optical or magnetic memory means for massstorage of a plurality of audiovisual pieces selectable from any ofthese devices—is characterized by the fact that each of theseaudiovisual devices (8) has interactive means for communication with theuser to select a piece or a menu, payment means, a computer networkcard, a permanent semiconductor memory containing a multitask operatingsystem including at least one hard disk access management task in whichthe order to play a piece resulting from a selection is handled as ahard disk sequential access task and declaration of the hard disk as aperipheral corresponding to the network card of the device, in order toallow a request to server (9) to be sent through the network forprocessing; the server includes a multitask operating system, apermanent mass memory of the magnetic or optical type, a network card bywhich the requests from different devices (8) are received, and theoperating system processes these disk access requests produced by thedevices as actual disk access requests.

[0008] Another feature of the invention is that in the operating systemof each audiovisual device, the declaration of the telecommunicationsmodem belonging to a telecommunications access task as peripheralcorresponds to that of the network card and when a telecommunicationsaccess request is made at the level of a device, the network card ofthis device transmits this request to the server which itself has atleast one telecommunications modem.

[0009] According to another feature, the audiovisual device is assuredbeforehand by a request that the modem card of the server be available.

[0010] According to another feature, the transmission speed of eachnetwork card and the buffers of video and audio control circuits aredimensioned to allow exchange of data with a transmission ratesufficient for video animation on a network containing at least eightaudiovisual devices.

[0011] According to another feature, each audiovisual device has a touchscreen and its interface software connected as an interactive means ofcommunication with the user.

[0012] According to another feature, the network has as many serverseach linked to a hard disk as it does servers corresponding to thenumber (multiple of eight) of audiovisual devices.

[0013] According to another feature, the operating system of each serveris linked to a switching means making it possible to decide whether thedata supplied in response to the request of one network device are givento all the network devices or only to those devices which transmitted arequest.

[0014] According to another feature, the server is equipped with meansfor audio or video performance of a piece, payment means, and means forinteractive communication with a user or network manager.

[0015] Other advantages and features of the invention will be discussedin the description below, with reference to the attached drawings, givenby way of an illustrative example but not limited to one embodiment ofthe invention, in which:

[0016]FIG. 1 shows a circuit diagram of the network according to theinvention;

[0017]FIG. 2 shows a schematic of the circuits which comprise anaudiovisual device of the network;

[0018]FIG. 3 shows a schematic of the circuits which comprise a serverof the network;

[0019]FIG. 4 shows the organization of the multitask system whichmanages the hardware and software means of each of the devices orservers of the network;

[0020]FIG. 5 shows a flowchart which describes how the multitaskoperating system functions;

[0021]FIG. 6 shows a flowchart which describes how the activities oftasks in the multitask system are verified;

[0022]FIG. 7 shows the flowchart which describes task queuing.

[0023] Preferably, but in a nonrestrictive manner, the audiovisualreproduction system uses the components cited above and numberedhereafter as in FIG. 1.

[0024] The system is comprised of a plurality of audiovisual devices (8₁, 8 ₂, 8 _(i), 8 ₁₆) linked to one another and via a computer server toat least one server (9 ₁, 9 ₂)

[0025] There are two types of servers (9 ₁, 9 ₂) which can be linked tolocal network (10), master servers (9 ₁) and mirror servers (9 ₂) Masterservers (9 ₁) are those which are actively involved with the localnetwork. They are the ones which receive requests from the jukeboxes (8)and which do the work.

[0026] The job of the mirror servers (9 ₂) is to clone the masterservers (9 ₁). They must be perfectly synchronized with their masters tobe ready for any change. When they detect that the master server (9 ₁)is no longer responding to the requests of the jukeboxes (8), they mustmake distress calls to the network administrators in order to take overfor the masters until the latter are operating normally again.

[0027] Each server (9 ₁, 9 ₂) is comprised of a central microprocessor(1 in FIG. 3) which is, for example, a high-performance PC-compatiblesystem, the choice for the embodiment having fallen on an Intel 80486DX/2 system which has storage means and the following characteristics.

[0028] compatibility with the local Vesa bus,

[0029] processor cache memory: 256 kO,

[0030] 100 Mbit network card (71)

[0031] high performance parallel and serial ports,

[0032] 32-bit type SCSI/2WIDE bus controller,

[0033] 32 MO battery backedup static RAM.

[0034] The operating system of the network cadrs must be a local networkserver such as NOVELL, OS/2 LAN SERVER, UNIX or any other similaroperating system.

[0035] This network server software allows access, exchange and sharingof data and equipment resources in an orderly manner by applyingpriorities and rules of access to each of the customers connected to thelocal network.

[0036] Any other central processor with equivalent or better performancecan be used in the invention.

[0037] The central unit (1, FIG. 3) of the server controls and managesnetwork control circuit (7), telecommunications control circuit (4),input control circuit (3), and mass storage control circuit (2). Ifserver (9) must operate as a jukebox, it is possible to add audiocontrol circuit (5) and display means control circuit (6) of the sametype as of devices (8). The display means consist essentially of 14 inch(35.56 cm) flat screen video monitor (62) without interleaving of theSVGA type, with high resolution and low radiation, which is used forimage reproduction (for example, the covers of the albums of the musicalselections), graphics or video clips.

[0038] For maintenance, server (9) uses external keyboard (34) which canbe linked to the server which has for that purpose a keyboard connector,controlled by interface circuit (3).

[0039] Mass storage means (21) using high-speed, high-capacity SCSI-typehard disks are connected to the storage means already present in themicroprocessor of server (9). These means are used to store digitizedand compressed audiovisual data.

[0040] High-speed telecommunications modem circuit (41) of at least 28.8Kbps is incorporated into server (9) to authorize the link to a networkfor distribution of audiovisual data controlled by a central systemcovering several servers.

[0041] Each audiovisual device (8) has one central microprocessor unit(1, FIG. 2) which is, for example, a high-performance PC-compatiblesystem. The choice for the embodiment has fallen on an Intel 80486 DX/2system which has storage means and the following characteristics:

[0042] compatibility with the local Vesa bus,

[0043] processor cache memory: 256 kO,

[0044] 100 Mbit network card (71)

[0045] 32 MO battery-backed static RAM.

[0046] high performance parallel and serial ports,

[0047] Any other central processor with equivalent or better performancecan be used in the invention.

[0048] This central unit controls and manages audio control circuit (5),input control circuit (3), computer network control circuit (7) anddisplay means control circuit (6). The display means consist essentiallyof a 14 or 15 inch (35.56 cm) flat screen video monitor (62) withoutinterleaving of the SVGA type, with high resolution and low radiation,which is used for image reproduction (for example, the covers of thealbums of the musical selections), graphics or video clips.

[0049] To reproduce the audio data of musical selections, the devicesand possibly the server(s) have loudspeakers (54) which receive thesignal of an amplifier-tuner (53) linked to electronic circuit (5) ofthe music synthesizer type intended to support a large number of inputsources while providing one output with CD (compact disk)-type quality,such as for example the microprocessor multimedia audio adapter of the“Sound Blaster” card type SBP32AWE by Creative Labs Inc to which twomemory buffers (56, 57) are added for a purpose described below. Thiscircuit (5) has the function of decompressing the digital data arrivingvia the network.

[0050] Likewise the display means control circuit also has two buffermemories (66, 67) for a purpose described below.

[0051] A ventilated, thermally controlled power supply of 240 wattspowers each device or server. This power supply is protected from surgesand harmonics.

[0052] Each audiovisual device (8) and possibly the server(s) (9)manage—via input controller circuit (3)—an “Intelli Touch” 14-inch(35.56 cm) touch screen (33) from Elo Touch Systems Inc. which includesa glass coated board using “advanced surface wave technology” and an ATtype bus controller. This touch screen allows, after having displayed onvideo monitor (62) or television screen (61) various selection data usedby the customers, as well as management command and control informationused by the system manager or owner. It is likewise used on each device(8) for maintenance purposes in combination with external keyboard (34)which can be connected to the device which has a keyboard connector forthis purpose, controlled by key lock (32) via interface circuit

[0053] Input circuit (3) of at least one of devices (8) of the networklikewise interfaces with a remote control set (31) composed for exampleof:

[0054] an infrared remote control from Mind Path Technologies Inc., anemitter which has 15 control keys for the microprocessor system and 8control keys for the projection device.

[0055] an infrared receiver with serial adapter from Mind PathTechnologies Inc.

[0056] A fee payment device (35) from National Rejectors Inc. islikewise connected to input interface circuit (3). It is also possibleto use any other device which allows receipt of any type of payment bycoins, bills, tokens, magnetic chip cards or a combination of means ofpayment.

[0057] To house the circuits, each device has a chassis or frame ofsteel with external customizable fittings.

[0058] Besides these components, wireless or wired microphone (55) isconnected to audio controller (5) of each device; this allowstransformation of the latter into a powerful public address system orpossibly a karaoke machine. Likewise a wireless loudspeaker system canbe used by the system.

[0059] Remote control set (31) allows the manager, for example frombehind the bar, to access and control various commands such as:

[0060] microphone start/stop command,

[0061] loudspeaker muting command,

[0062] audio volume control command;

[0063] command to cancel the musical selection being played.

[0064] Two buffers (56, 57) are connected to audio controller circuit(5) to allow storage of information corresponding to a quarter of asecond of sound each in alternation. Likewise two buffers (66, 67) arelinked to each video controller circuit (6), each of which is able tostore a tenth of a second of video in alternation. Finally, inputinterface buffer (36) is connected to each input interface (3) of eachdevice (8) or server (9).

[0065] The system operating software of each device (8) or server (9)was developed around a library of tools and services largely oriented tothe audiovisual domain in a multimedia environment. This libraryadvantageously includes a powerful multitask operating system whicheffectively authorizes simultaneous execution of multiple fragments ofcode. This operating software thus allows concurrent execution—in anorderly manner and avoiding any conflict—of operations carried out onthe display means or audio reproduction means as well as management ofthe telecommunications lines via the distribution network. In addition,the software has high flexibility.

[0066] The digitized and compressed audiovisual data are stored instorage means (21) of server (9).

[0067] Each selection is available in two digitized formats: with hi-fiquality or CD quality.

[0068] The operating software of each device (8) is installed in thebattery backed-up static RAM of each device (8), while the operatingsoftware of server (9) can be backed up on hard disk (21) and loaded foroperation in the server's RAM.

[0069] It must be noted that the specific tasks of the modules whichmake up the operating system are executed simultaneously in anenvironment using the multitask operating system. Consequently, theorganizational chart indicates specific operations which a module mustperform and not a branch to this module which would invalidate all theoperations performed by the other modules.

[0070] The first module, labeled SSM, is the startup module. This moduledoes only one thing, and consequently it is loaded automatically whenthe device or server is powered up and then directly re-enters the “inservice” mode of the module labeled RRM.

[0071] The RMM module is the module of the “in service” mode which isthe mode of operation which the system enters when its registrationnumber has been validated. In this mode, device (8) or server (9) isready to handle any request which can be triggered by various predefinedevents such as:

[0072] users touching the screen of device (8), transferring foregroundsession control to the CBSM module from the customer browsing andselection mode,

[0073] telecommunications call requests by the TSM telecommunicationsservices module,

[0074] Device (8) or server (9) remains in the “in service” mode untilone of the events cited above takes place.

[0075] The CBSM module is the customer browsing and selection mode.Access to this module is triggered from the “in service” mode when thecustomer touches the screen. The display allows the user to view a menuprovided for powerful browsing assisted by digitized voice messages toguide the user in his choice of musical selections.

[0076] The TSM module is the telecommunications services mode modulebetween the network server and a central system covering several serversbelonging to different networks. The module allows management of allmanagement services available on the distribution network. All the tasksspecific to telecommunications are managed as background tasks of thesystem. These tasks always use only parts of the processing timeremaining once the system has completed all its foreground tasks. Thus,when the system is busy with one of its higher priority tasks, thetelecommunications tasks automatically will try to reduce thelimitations on system resources and recover all the microprocessorprocessing time left available.

[0077] The SPMM module allows management of musical, song or videoselections queued by the system for execution in the order of selection.

[0078] The multitask operating system is the essential component forallowing simultaneous execution of multiple code fragments and formanaging priorities between the various tasks which arise.

[0079] This multitask operating system is organized as shown in FIG. 4around a kernel comprising a module (11) for resolving prioritiesbetween tasks, task scheduling module (12), module (13) forserialization of hardware used, and process communications module (14).Each of the modules communicates with applications programminginterfaces (15) and database (16). There are as many programminginterfaces as there are applications. Thus, module (15) includes firstprogramming interface (153) for touch screen (33), second programminginterface (154) for the keyboard, third programming interface (155) forpayment device (35), fourth programming interface (156) for audiocontrol circuit (5), fifth programming interface (157) for video controlcircuit (6) and last interface (158) for computer network controlcircuit (7).

[0080] It should be noted that the programming interface of the networkcard is supplied with the card when a network kit is purchased and thatthe network card is declared to the operating system as the peripheralcomprising the hard disk or the modem, telecommunication card of eachaudiovisual device (8). Thus each operating system of each device (8),after calling a telecommunications procedure or hard disk accessprocedure following a selection, triggers a network communicationsession in which the network card of the server will make the calledresource available to each audiovisual device (8).

[0081] Five tasks with a decreasing order of priority are managed by thekernel of the operating system, the first (76) for the videoinputs/outputs has the highest priority, the second (75) of level tworelates to audio, the third (74) of level three to telecommunications,the fourth (73) of level four to interfaces and the fifth (70) of levelfive to management. These orders of priority will be considered bypriority resolution module (11) as and when a task appears anddisappears. Thus, as soon as a video task appears, the other tasksunderway are suspended, priority is given to this task and all theresources are assigned to the video task. At the output, video task (76)is designed to unload the video files from mass memory (21)alternatively to one of two buffers (66, 67) of device (8) which madethe request, whereas other buffer (67 or 66) is used by video controllercircuit (6) of device (8) having made the request to produce the displayafter data decompression. At the input, video task (76) from server (9)is designed to transfer data received in telecommunications buffer (46)of server (9) to mass storage (21) of server (9). It is the same foraudio task (75) on the one hand at the input between telecommunicationsbuffer (46) and the buffer (26) of mass memory (21) and on the otherhand at the output between buffer (26) of mass memory (21) of server (9)and one of two buffers (56, 57) of audio controller circuit (5) ofdevice (8) which made the request.

[0082] Task scheduling module (12) of each device (8) or server (9) willnow be described in conjunction with FIG. 5. In the order of prioritythis module performs first test (761) to determine if the video task isactive, i.e, if one of video buffers (66, 67) is empty. In the case of anegative response the task scheduling module passes to the followingtest which is second test (751) to determine if the audio task isactive, i.e, if one of buffers (56, 57) is empty. In the case of anegative response third test (741) determines if the communication taskis active, i.e., if buffer (46) is empty. After a positive response toone of the tests, task scheduling module (12) at stage (131) fillsmemory access request queue (13) and at stage (132) executes thisrequest by reading or writing between mass storage (21) of server (9)and the buffer corresponding to the active task of device (8), thenloops back to the first test. When test (741) on communications activityis affirmative, scheduler (12) performs test (742) to determine if it isa matter of reading or writing data in the memory. If yes, the read orwrite request is placed in a queue at stage (131). In the opposite case,the scheduler determines at stage (743) if it is transmission orreception and in the case of transmission sends via a networkcommunication procedure at step (744) a block of data to server (9) fortransmission by the latter to the central system covering severalservers. In the case of reception the scheduler verifies at stage (746)that the server buffers are free for access and in the affirmative sendsa message to the central server to accept reception of a data block atstage (747). After receiving a block, an error check (748) of the cyclicredundancy check (CRC) type is executed. The block is rejected at stage(740) in case of error, or accepted in the opposite case at stage (749)by sending a message corresponding to the central system indicating thatthe block bearing a specific number is rejected or accepted, then loopsback to the start tests. When there is no higher level task active, atstage (731 or 701) the scheduler processes interface or managementtasks.

[0083] Detection of an active task or ready task is done as shown inFIG. 6 by a test respectively (721 to 761) on each of respectivehardware or software buffers (26) of the hard disk, (36) of theinterface, (46) of telecommunications, (56 and 57) of audio, (66 and 67)of video which are linked to each of respective controller circuits (2,3, 4, 5, 6, 7) of each of the hardware devices linked to centralprocessor (1).

[0084] Test (721) makes it possible to see whether the data are presentin the input and output memory buffer of the disk, test (731) makes itpossible to see whether data are present in the hardware or softwarememory buffers of the customer interface device, test (741) makes itpossible to see whether data are present in the software or hardwarememory buffers of the telecommunications device, test (751) makes itpossible to determine whether data are present in the hardware orsoftware memory buffer for direction, and test (761) makes it possibleto see whether data are present in the hardware or software memorybuffers of the video device.

[0085] If one or more of these buffers are filled with data, scheduler(12) positions respective status buffer or buffers (821) for the harddisk, (831) for the interface, (841) for telecommunications, (851) foraudio, (861) for video corresponding to the material in a logic stateindicative of the activity. In the opposite case the scheduler statusbuffers are returned at stage (800) to a value indicative of inactivity.

[0086] The operating status of server (9) or respectively of device (8)is kept on hard disk (21) of server (9) or respectively in the batterybacked-up memory of device (8).

[0087] Each time a notable event occurs, the system immediatelyregisters it on the permanent storage means.

[0088] Thus, in the case in which an electrical fault or hardwarefailure occurs, the system will accordingly restart exactly at the samelocation where it had been interrupted.

[0089] Events which trigger back-up of the operating status are:

[0090] insertion of money (crediting);

[0091] addition of a selection to the queue;

[0092] end of a selection (change from the selection currently beingplayed).

[0093] The file is then in a machine format which can only be read bythe unit and does not occupy more than 64 octets.

[0094] The number and type of active tasks is indicated to scheduler(12) by execution of the selection management module SPMM whoseflowchart is shown in FIG. 7. The management exercised by this modulebegins with test (61) to determine if selections are in the queue.

[0095] Consequently, if test (61) on the queue determines thatselections are waiting, when a customer chooses a title he wishes tohear, it is automatically written in a queue file of the system on harddisk.

[0096] Thus, any selection made will never be lost in case of anelectrical failure. The system plays (reproduces) the selection in itsentirety before removing it from the queue file.

[0097] When the selection has been reproduced in its entirety, it isremoved from the queue file and written in the system statistics filewith the date and time of purchase as well as the date and time at whichit was played.

[0098] Immediately after transfer of the completed selection to thestatistics file, the device checks if there are others in the queuefile. If there is another, the device begins immediately to play theselection.

[0099] Processing continues with test (65) conducted to determine if theselection contains an audio scenario. If yes, at stage (651) thisscenario is written in the task queue of scheduler (12). If not, orafter this entry, processing is continued by test (66) to determine ifthe selection contains moving images. If yes, the video scenario iswritten at stage (661) in the task queue of scheduler (12). If no or ifyes after this entry, processing is continued by test (64) to determineif the selection contains still graphics. If yes, at stage (641) thisgraphic presentation scenario is written in the task queue of scheduler(12). If no or if yes after this entry, processing is continued by test(63) to determine if the selection contains an advertising scenario. Ifyes, at stage (631) the scenario is written in the task queue ofscheduler (12). Thus scheduler (12) notified of uncompleted tasks canmanage the progression of tasks simultaneously.

[0100] Due on the one hand to the task management mode assigning highestorders of priority to video tasks requiring the most resources, on theother hand to the presence of hardware or software buffers assigned toeach of the tasks to temporarily store data, the presence of statusbuffers relating to each task, and communication between each device anda server via the computer network, it is possible to transfer costlyresources necessary for certain tasks of devices (8) to single centralunit (9) which also has a multitask operating system.

[0101] A basic server (9) is designed to service a local network havingup to eight customer jukeboxes. With addition of appropriateperipherals, such as supplementary hard disks, one server can serve amaximum of 8 additional jukeboxes. To add more jukeboxes, it is possibleto create local network environments which have several servers whichshare tasks. Thus it is possible to create environments capable ofmeeting any need.

[0102] A completely equipped server has sufficient resources toadminister 16 jukeboxes. A server can support up to 7 disks which cancontain as many selections as there is available space needed for thetype of selection, with the knowledge that an audio selection and itsgraphic part require 3.4125 Mbits of available disk space, and an audioand video selection requires 39.568 Mbits of available disk space.

[0103] In order to circumvent these limitations and meet the needs ofestablishments such as hotel complexes which sometimes have severalhundred rooms, it is possible to use mass storage technologies such asRAID to back up the selections and/or network configurations withmultiple servers in order to serve the jukeboxes.

[0104] It is also possible to add additional telecommunicationsperipherals (41) such as modems in order to satisfy the network'sadditional needs for telecommunications to the outside.

[0105] The network allows the server to assume responsibility forcarrying out several tasks common to each jukebox in order to avoidredundancy of work, computer operations and equipment.

[0106] The local network also serves as an important link between allthe jukeboxes by making connections which allow all data common to allthe jukeboxes to be kept and made accessible to each of them.

[0107] The common data kept on a server are either audio/videoselections or statistics of use of the purchases of each jukebox, orstatistics on the audio/video selections.

[0108] The jukebox or audiovisual device (8) on the one hand has notelecommunications peripherals because the latter are centralized atserver (9), but it does make requests to server (9) which processes themas a priority; on the other hand, it does not have the disk spacerequired to store audio/video selections, since the selections arecentralized at server (9) so that they may be shared with all thejukeboxes of the local network.

[0109] Network jukebox (8) needs very little permanent storage space,since all data will now be centralized, allowing units without hard diskto be produced and thus reducing maintenance by eliminating those partsmost likely to break down. In jukebox (8) without a hard disk, apermanent memory region contains all the information and operatingprogram necessary to make connections with the server and start-up thejukebox operating system.

[0110] This permanent memory can be in the form of an EEPROM, staticmemory banks which are backed up by batteries or even cards called HARDCARDS which are static memory banks backed up by batteries withfunctions allowing the tasks of a hard disk to be cloned.

[0111] The operating system of jukebox module (8) is assured of havingthe resources necessary to do its work. To do this it must manage thestatus of links with centralized peripherals and if necessary makerequests to the server requesting that the appropriate connections bemade between the jukebox and the required peripheral. If the resources,for example, telecommunications resources, are not in use by a jukebox,then server (9) will provide exclusive links to the jukebox.

[0112] Once the connection has been made, jukebox (8) can do its work asif the resource were its own. Once the jukebox (8) finishes its work, itsends a request to the server to be disconnected from the resource, thusmaking it available for other jukeboxes (8) in the network.

[0113] The order and logic used to provide distribution and accessprivileges to the ordered resources are controlled by the networkoperating system which is on server (9).

[0114] Thus a switching device such as a hardware or software key allowsthe network operator to decide whether server (9) shall play the sameselection on all devices (8) of the network or to let each device (8)play a different selection. In this latter case, hard disk resourceswill be accessed time-shared between each device (8), since buffers (56,57; 66, 67) of each device (8) have sufficient capacity to awaitsubsequent access without there being discontinuity in the audio orvisual representation.

[0115] Moreover, the multitask operating system, which includes alibrary containing a set of tools and services, considerably facilitatesoperation due to its integration in the memory storage means and theresulting high degree of flexibility. In particular, this allows amultimedia environment to be created by simply and efficiently managingaudio reproduction, video or graphics display, and video animation. Inaddition, since the audiovisual data are digitized and stored in theserver's storage means alone, the cost of the network is considerablyreduced.

[0116] Likewise, transfer of hardware necessary for thetelecommunications function of each device (8) on the network servergreatly reduces the cost and by using a computer network with atransmission speed of 100 Mbit/s makes it possible to servesimultaneously at least eight devices which can all simultaneouslyreproduce a different video animation piece on each of the devices, withthe knowledge that each video animation requiring a transmission speedof 10 Mbit/s.

[0117] This would not have been possible with the ISDN network of patentWO 94/15416, with a transmission speed which is on the order of 1Mbit/s, insufficient even for video animation. The same applies to anyother line for long distance data transmission.

[0118] Any modification by one skilled in the art is likewise part ofthe invention. Thus, regarding buffers, it should be remembered thatthey can be present either physically in the circuit to which they areassigned or implemented by software by reserving storage space in thesystem memory.

1. Audiovisual distribution system for playing an audiovisual piece onat least one audiovisual device (8) from among a plurality ofaudiovisual devices, each comprised of audio or video means for playinga piece and linked to a central computer server (9) containing opticalor magnetic memory means for mass storage (21) of a plurality ofaudiovisual pieces selectable from any of these devices, characterizedin that each of these audiovisual devices (8) has means (33) forinteractive communication with the user to select a piece or a menu,payment means (35), computer network card (71), a permanentsemiconductor memory containing a multitask operating system includingat least one hard disk access management task in which the order to playa piece resulting from a selection is handled as a hard disk sequentialaccess task and declaration of the hard disk as a peripheralcorresponding to the network card of the device, in order to allow arequest to the server (9) to be sent through the network for processing,said server being comprised of a multitask operating system, permanentmass memory (21) of the magnetic or optical type, network card (71) bywhich the requests from different devices (8) are received, saidoperating system processing these disk access requests produced by thedevices as actual disk access requests.
 2. Audiovisual distributionsystem according to claim 1, wherein in the operating system of eachaudiovisual device (8), declaration of the telecommunications modembelonging to a telecommunications access task as peripheral correspondsto that of the network card and when a telecommunications access requestis made at the level of device (8), the network card of this devicetransmits this request to the server (9) which itself has at least onetelecommunications modem (41).
 3. Audiovisual distribution systemaccording to claim 2, wherein audiovisual device (8) assures itselfbeforehand by request that the modem card of server (9) is available. 4.Audiovisual distribution system according to one of claims 1 through 3,wherein the transmission rate of each network card (71) and the buffersof video and audio control circuits are dimensioned to allow exchange ofdata with a transmission rate sufficient for video animation on anetwork containing at least eight audiovisual devices.
 5. Audiovisualdistribution system according to one of claims 1 through 4, wherein eachaudiovisual device has touch screen (33) and its interface software(153) connected as an interactive means of communication with the user.6. Audiovisual distribution system according to one of claims 1 through5, wherein the network has as many servers (9) each linked to a harddisk (21) as it does servers corresponding to the number (multiple ofeight) of audiovisual devices (8).
 7. Audiovisual distribution systemaccording to one of the preceding claims, wherein the operating systemof each server (9) is linked to a switching means making it possible todecide whether the data supplied in response to the request of a networkdevice (8) are delivered to all the network devices or only to thosedevices which transmitted a request.
 8. Audiovisual distribution systemaccording to one of claims 1 through 7, wherein the server is equippedwith means (5, b) for audio or video performance of a piece, paymentmeans (35), and means of interactive communication with a user ornetwork manager.